Speed-reduction gearing



June 4, 1929. E. DU PONT 1,715,908

SPEED REDUCTION GEARING Filed June 24, 1927' CII 'unit of minimum length.

Patented `lune 4, 1929.

p UNITED STATES PATENT OFFICE. g

ELEUTHERE PAUL DU PONT, OF MONTCHANIN, DEIIAW'ARE.`

SPEED-REDUCTIGN GEARING.

Applieationled June 211,

My invention relates to power transmission gearing and has for its purpose to reduce the speed between a driving shaft and a driven shaft. A more especial object is to provide reduction gearing that will operate quietly, avoid the necessity for bearings between the two shafts and provide a compact and simple the invention is to so construct the gearing that it may be adjusted, at will, either to operateas a speed reduction gearing or to turn Vbodily with both shafts so asto enable the driven shaft to be operated at the same speed as the driving shaft.

The invention is especially adapted to automobile transmissions and its preferred location is between the'clutchfcontrolled driving shaft and the shaft that connects with the regular multiple-gear transmission, although it may be arranged to be applied at any other point between the motor Vand rear aXle.

In the drawing, which showsa preferred en'ibodiinent of the invention and also one preferred application thereof to an automobile transmissionv f F ig. 1 is an elevational view showing the invention applied to an automobile transmission. l

Fig.' 2 is a longitudinal sectional view of reduction gearing embodying my invention.

Fig` 3 is a section on the line 3 3 of Fig. 2.

The driving shaft a, which receives its power from any source,`as from a motor m, and the driven shaft b, are held in alignment by an end bearing connection lc between them and by the two aligning concentric bearings z' and j (carrying a gear housing it), which are mounted upon the respective shafts. .Shaft a carries a pinion 0, which engages an internal gear d, to which is attached a pinion which meshes with an internal gear g on shaft b. The internal gear d and the pinion f are mounted upon the eccentric bearings z' and In Fig. l are shown a clutch n for connecting the sha-ft of motor m to shaft a and a housing 0 for a regular three-speed gear transmission, which may be connected to the rear aXle p by the usual connections r.

Means should be provided to lock the case or housing la to one of the shafts a or b, so that it will turn therewith, and also to unlock the housing from such shaft and lock it to some supporting member that will hold it from turning. In Fig. l, I have provided, for this purpose, a lever t carrying two arms Another object of i 1927. semi N0.` 201,o51. A

u and o. Arm a operates a clutch w to conneet shaftr a and housing L. Arm v is adapted to engage and interlock a lug m on housing /iand ai pair yof lugs v/ on housing` 0. By moving lever t in onedir'ection,- housing L is locked to shaft a and unlocked from housing 0. yBy moving lever t in the other direction,

housing It is locked to housing 0 and unlocked from shaft a. y* I vWhen housing/L isflocked to shaft a (or to shaft Ab if means should be provided to lock it thereto) the gears become inoperative and the entire mechanism revolves in unison and shaft Z) is driven from shaft a as if it were directly secured thereto. n y y When housing 7L is locked'to housing 0 (or toV any other fixed support the gearsrevolve and shaft 7) is driven ,at a reducedfspeed. That is, the internal gear d, being of greater diameter' than' pinion c (carried by shaft a) will. be ydriven at a lower speedjthan shaft a; and pinion (carried by internal gear (l) being of smallerdiameter tlian'internal gear I() (carried by shaft 7)), will drive shaft Z) rat a still Vlower speed. i' i Vhen my improved train of gears is in,-

Internal gears run much morequietly than g spur gears. Further,`my arrangement of internal gears does not lengthen thelay-out as much as other arrangements of'internal gears that require bearings inbetween. the 'driving and 'driven'shafts well as compact. 'i

Having now fully described my invention what I claim and desire to Patent is:

1. Speed change gearing comprising a driving shaft and a driven shaft, a pinion turning with one shaft, an internal turning with the other shaft, an interme iate rotary member comprising an internal gear in operative engagement with said pinion and a pinion in operative engagement with the first named internal gear, eccentrics sleeved on the respective shafts and on which the intermediate rotary member is sleeved, and means to secure the eccentries in fixed relation to one of the shafts or, alternatively, to secure the eecentrics in relatively non-rotatable position, thereby enabling the driving shaft to drive the driven shaft at a one to one ratio or at a different speed.

protect by Letters 2. Speed change gearing comprising a driving shaft and a driven shaft adjacent thereto and aligning therewith; eccentrics on the shafts; a pinion on one shaft and an internal gear on the other shaft, said pinion and gear being on the adjacent ends of their respective shafts and the internal gear opening away from the pinion; an intermediate rotary member sleeved on said eccentrics and comprising an internal gear in operative engagement with said pinion and opening toward and adjoining the first named internal gear, a pinion in operative engagement wit-h the first named internal gear, and a connecting element between the second named internal gear and the second named pinion: the described arrangement providing a transmission gearing of minimum length.

3. Speed change gearing comprising a driving shaft and a driven shaft adjacent thereto. and aligning therewith; eccentrics on the shafts; a pinion on one shaft and an internal gear on the other shaft, said pinion and gear being on the adjacent ends of their respective shafts and the internal gear opening away from the pinion; an intermediate rotary member sleeved on said eccentrics and comprising an internal gear in operative engagement with said pinion and opening toward and adjoining the first named internal gear, a pinion in operative engagement with the first named internal gear, and an element surrounding the first named internal gear and connecting the second named internal gear and the second named pinion, a housmg enclosing said gears and pinions and in fixed relation to said eccentrics, and means to lock one of the shafts in fixed relation to the housing or, alternatively, to unlock said shaft andallow said train of gearing to drive the driven shaft at reduced speed.

4:. Speed change gearing comprising a driving shaft and a driven shaft aligned therewith, eccentrics in which the respective shafts turn, an intermediate rotary member sleeved on the eccentrics and spanning the ends of the two shafts, said member comprising an internal gear and a pinion, a pinion turning with one shaft and adapted to drive said internal gear, an internal gear turning with the other shaft and adapted to be driven by the first named pinion, and means selectively operative either to cause the driving shaft to drive said driven shaft through the train of gearing at a different speed or to lock the driving shaft to the 'driven shaft to drive the latter at the same speed.

5. Speed change gearing comprising a driving shaft and a driven shaft, eccentrics sleeved'thereon, a pinion turning with one shaft, an internal gear turning with the other shaft, an intermediate rotary member sleeved on said eccentrics and comprising an internal gear arranged to mesh with said pinion and a pinion arranged to mesh with the first named internal gear, and means selectively operative either to cause the driving shaft to drive said driven shaft through the train of gearing at a different speed or to lock the driving shaft to the driven shaft to drive the latter at the same speed.

6. Speed change gearing comprising a driving shaft and a driven shaft aligned therewith, eccentrics sleeved thereon, a pinion turning with oneshaft, an internal -ear turning with the other shaft, an interme iate rotary member sleeved on said eccentrics and spanning the two shafts and comprising an internal gear arranged to mesh with said pin'- ion and a pinion arranged to mesh with the first named internal gear, and means selectively operative either to cause the driving shaft to drive said drivenV shaft through the train of gearing at a different speed or to lock the driving` shaft to the driven shaft to drive the latter at the same speed.

In testimony of which invention, I have hereunto set my hand, at Montchanin, Delaware, on this 22nd day of June, 1927.

ELEUTHERE PAUL DU PONT. 

